Asapiprant is an antagonist of the prostaglandin D1 (PGD1) receptor (DP1; Ki = 0.44 nM).1 It is selective for DP1 over DP2, as well as the thromboxane A2 (TXA2), prostaglandin I2 (PGI2), and prostaglandin E1-4 (PGE1-4) receptors (Kis = >5,000, >4,800, >6,300, and 120->6,600 nM, respectively). Asapiprant (1 and 3 mg/kg) reduces PGD2-induced increases in nasal resistance in a guinea model of allergic rhinitis. It reduces nasal secretion, when administered at doses of 3 and 30 mg/kg, and antigen-induced cell infiltration in nasal lavage fluids, when administered at 3 and 10 mg/kg, in a guinea pig model of allergic rhinitis induced by ovalbumin. Asapiprant (10 mg/kg) also decreases airway hyperresponsiveness, inflammatory cell infiltration in bronchoalveolar lavage fluid (BALF), and mucin production in a rat model of ovalbumin-induced asthma.
1.Takahashi, G., Asanuma, F., Suzuki, N., et al.Effect of the potent and selective DP1 receptor antagonist, asapiprant (S-555739), in animal models of allergic rhinitis and allergic asthmaEur. J. Pharm.765(15)15-23(2015)